Field of Invention
This invention concerns a novel recombinant streptavidin-Protein A chimeric protein which allows specific conjugation or labeling of antibody molecules with biological materials or, conversely, labeling such materials with antibodies. The chimeric protein can be efficiently expressed in Escherichia coli and can be purified by simple procedures. The chimeric protein purified to homogeneity has full biotin binding ability, and binds one to two immunoglobulin molecules per subunit.